BGE has developed a tool called BGE Profiler that will calculate hourly loads. Users can input hourly weather data (Drybulb in the winter and WTHI in the summer) and a date and BGE Profiler will calculate static weather-sensitive hourly loads for that date. BGE, however, does not provide the hourly weather data and users of the BGE Profiler must obtain this information on their own. The tool has been set up in Microsoft Excel® and must be downloaded to use. Instructions for use are located on the spreadsheets:
BGE continues to update this data with the latest hourly weather sensitive response functions. The latest update is effective on June 1, 2014 for the non-summer equations and May 31, 2015 for the summer equations. The latest update for all customer segments uses data for the period June 1, 2014 to May 31, 2015.
|R||6/1/14 - 5/31/15|
|RL||6/1/14 - 5/31/15|
|RH||6/1/14 - 5/31/15|
|RLH||6/1/14 - 5/31/15|
|G||6/1/14 - 5/31/15|
|GS||6/1/14 - 5/31/15|
|GL||6/1/14 - 5/31/15|
WTHI Weather Definition:
Hourly wet bulb and dry bulb temperature readings for the Baltimore area are used to produce an hourly Weighted Temperature Humidity Index (WTHI). This measure of weather takes account of both the dry bulb temperature and the humidity conditions contemporaneous with the hourly period under examination, and also takes account of the dry bulb temperatures and humidity conditions during the previous 48 hours. The formulas used for Temperature Humidity Index (THI) are:
- THIt = 17.5 + .55*DryBulbt + .2*WetBulbt
For WTHI, the current hour’s THI gets a weight of 10, the previous 24 hour’s THI gets a weight of 3, and the weight for the previous 48 hours is 1. These data are a main driver in explaining electric usage.